Long-term all-cause and cause-specific mortality for four bariatric surgery procedures

Abstract

Objective: This retrospective study incorporated long-term mortality results after different bariatric surgery procedures and for multiple age at surgery groups.

Methods: Participants with bariatric surgery (surgery) and without (non-surgery) were matched (1:1) for age, sex, BMI, and surgery date with a driver license application/renewal date. Mortality rates were compared by Cox regression, stratified by sex, surgery type, and age at surgery.

Results: Participants included 21,837 matched surgery and non-surgery pairs. Follow-up was up to 40 years (mean [SD], 13.2 [9.5] years). All-cause mortality was 16% lower in surgery compared with non-surgery groups (hazard ratio, 0.84; 95% CI: 0.79-0.90; p < 0.001). Significantly lower mortality after bariatric surgery was observed for both females and males. Mortality after surgery versus non-surgery decreased significantly by 29%, 43%, and 72% for cardiovascular disease, cancer, and diabetes, respectively. The hazard ratio for suicide was 2.4 times higher in surgery compared with non-surgery participants (95% CI: 1.57-3.68; p < 0.001), primarily in participants with ages at surgery between 18 and 34 years.

Conclusions: Reduced all-cause mortality was durable for multiple decades, for multiple bariatric surgical procedures, for females and males, and for greater than age 34 years at surgery. Rate of death from suicide was significantly higher in surgery versus non-surgery participants only in the youngest age at surgery participants.

Figure 1.

Retrospective study design and exclusions. Diagram indicating the exclusion criteria and number of exclusions for each variable listed. The counts in each line of the boxes represent the number of missing or non-qualifying data points out of the total records listed in the box above. Each record could have multiple missing values (such as missing age and BMI) and would be counted multiple times so that the total counts within a box do not add up to the total in the preceding box. This allows the counts to represent the amount of missing data for that variable.

Figure 2.

Mortality risk of bariatric surgery patients compared to non-surgery driver license applicant subjects stratified by sex. S = Surgery Patients; N = Non-surgery Subjects Non-external causes of death defined as Natural or Pending Investigation with specified codes listed under in the non-external causes of death categories (Supplementary Appendix Table 2). External causes of death defined as Suicide or Homicide or Accident or Missing (NA) with specified codes listed under in the external causes of death categories (Supplementary Appendix Table 2). All disease classifications were taken from the primary causes of death except diabetes and Alzheimer’s disease, which also used secondary causes of death. Malignant neoplasms used codes defined in Supplementary Appendix Table 1. Counts less than 11 are required by the Utah Department Health to be reported only as <11. HR: hazard ratio; CI: confidence interval; S: surgery group; N: non-surgery group.

Figure 3.

Mortality risk of bariatric surgery patients compared to non-surgery driver license applicant subjects stratified by age category (years) at surgery. S = Surgery Patients; N = Non-surgery Subjects Non-external causes of death defined as Natural or Pending Investigation with specified codes listed under in the non-external causes of death categories (Supplementary Appendix Table 2). External causes of death defined as Suicide or Homicide or Accident or Missing (NA) with specified codes listed under in the external causes of death categories (Supplementary Appendix Table 2). All disease classifications were taken from the primary causes of death except diabetes and Alzheimer’s disease, which also used secondary causes of death. Malignant neoplasms used codes defined in Supplementary Appendix Table 1. Counts less than 11 are required by the Utah Department Health to be reported only as <11. HR: hazard ratio; CI: confidence interval; S: surgery group; N: non-surgery group.

Figure 4.

Mortality risks of bariatric surgery patients compared to non-surgery driver license applicant subjects stratified by surgery type. S = Surgery Patients; N = Non-surgery Subjects Non-external causes of death defined as Natural or Pending Investigation with specified codes listed under in the non-external causes of death categories (Supplementary Appendix Table 2). External causes of death defined as Suicide or Homicide or Accident or Missing (NA) with specified codes listed under in the external causes of death categories (Supplementary Appendix Table 2). All disease classifications were taken from the primary causes of death except diabetes and Alzheimer’s disease, which also used secondary causes of death. Malignant neoplasms used codes defined in Supplementary Appendix Table 1. Counts less than 11 are required by the Utah Department Health to be reported only as <11. HR: hazard ratio; CI: confidence interval; S: surgery group; N: non-surgery group.